# Copyright 2008-2016 Free Software Foundation, Inc.
# This file is part of GNU Radio
#
# SPDX-License-Identifier: GPL-2.0-or-later
#


from codecs import open
from collections import namedtuple
from collections import ChainMap
import os
import logging
from itertools import chain
from typing import Type

from . import (
    Messages, Constants,
    blocks, params, ports, errors, utils, schema_checker
)
from .blocks import Block

from .Config import Config
from .cache import Cache
from .base import Element
from .io import yaml
from .generator import Generator
from .FlowGraph import FlowGraph
from .Connection import Connection
from .workflow import WorkflowManager

logger = logging.getLogger(__name__)


class Platform(Element):

    def __init__(self, *args, **kwargs):
        """ Make a platform for GNU Radio """
        Element.__init__(self, parent=None)

        self.config = self.Config(*args, **kwargs)
        self.block_docstrings = {}
        # dummy to be replaced by BlockTreeWindow
        self.block_docstrings_loaded_callback = lambda: None

        self._docstring_extractor = utils.extract_docs.SubprocessLoader(
            callback_query_result=self._save_docstring_extraction_result,
            callback_finished=lambda: self.block_docstrings_loaded_callback()
        )

        self.workflow_manager = WorkflowManager()
        self.blocks = self.block_classes
        self.domains = {}
        self.examples_dict = {}
        self.connection_templates = {}
        self.cpp_connection_templates = {}
        self.connection_params = {}

        self._block_categories = {}
        self._auto_hier_block_generate_chain = set()

    def __str__(self):
        return 'Platform - {}'.format(self.config.name)

    @staticmethod
    def find_file_in_paths(filename, paths, cwd):
        """Checks the provided paths relative to cwd for a certain filename"""
        if not os.path.isdir(cwd):
            cwd = os.path.dirname(cwd)
        if isinstance(paths, str):
            paths = (p for p in paths.split(':') if p)

        for path in paths:
            path = os.path.expanduser(path)
            if not os.path.isabs(path):
                path = os.path.normpath(os.path.join(cwd, path))
            file_path = os.path.join(path, filename)
            if os.path.exists(os.path.normpath(file_path)):
                return file_path

    def load_and_generate_flow_graph(self, file_path, out_dir=None, hier_only=False):
        """Loads a flow graph from file and generates it"""
        Messages.set_indent(len(self._auto_hier_block_generate_chain))
        Messages.send('>>> Loading: {}\n'.format(file_path))
        if file_path in self._auto_hier_block_generate_chain:
            Messages.send('    >>> Warning: cyclic hier_block dependency\n')
            return None, None
        self._auto_hier_block_generate_chain.add(file_path)
        try:
            flow_graph = self.make_flow_graph()
            flow_graph.grc_file_path = file_path
            # Other, nested hier_blocks might be auto-loaded here
            flow_graph.import_data(self.parse_flow_graph(file_path))
            flow_graph.rewrite()
            flow_graph.validate()
            if not flow_graph.is_valid():
                raise Exception('Flowgraph invalid')
            if hier_only and not flow_graph.get_option('generate_options').startswith('hb'):
                raise Exception('Not a hier block')
        except Exception as e:
            Messages.send('>>> Load Error: {}: {}\n'.format(file_path, str(e)))
            Messages.send_flowgraph_error_report(flow_graph)
            return None, None
        finally:
            self._auto_hier_block_generate_chain.discard(file_path)
            Messages.set_indent(len(self._auto_hier_block_generate_chain))

        try:
            if flow_graph.get_option('generate_options').startswith('hb'):
                generator = self.Generator(flow_graph, out_dir)
            else:
                generator = self.Generator(flow_graph, out_dir or file_path)
            Messages.send('>>> Generating: {}\n'.format(generator.file_path))
            generator.write()
        except Exception as e:
            Messages.send(
                '>>> Generate Error: {}: {}\n'.format(file_path, str(e)))
            return None, None

        return flow_graph, generator

    def build_example_library(self, path=None):
        self.examples = list(self._iter_files_in_example_path())

    def build_library(self, path=None):
        """load the blocks and block tree from the search paths

        path: a list of paths/files to search in or load (defaults to config)
        """
        self._docstring_extractor.start()

        # Reset
        self.blocks.clear()
        self.domains.clear()
        self.connection_templates.clear()
        self.cpp_connection_templates.clear()
        self._block_categories.clear()

        try:
            from gnuradio.gr import paths
            cache_file = os.path.join(paths.cache(), Constants.GRC_SUBDIR, Constants.CACHE_FILE_NAME)
        except ImportError:
            cache_file = Constants.FALLBACK_CACHE_FILE
        with Cache(cache_file, version=self.config.version) as cache:
            logger.debug("Building library from path: %s (config paths: %s)", path, self.config.block_paths)
            for file_path in self._iter_files_in_block_path(path):
                if file_path.endswith('.block.yml'):
                    loader = self.load_block_description
                    scheme = schema_checker.BLOCK_SCHEME
                elif file_path.endswith('.domain.yml'):
                    loader = self.load_domain_description
                    scheme = schema_checker.DOMAIN_SCHEME
                elif file_path.endswith('.tree.yml'):
                    loader = self.load_category_tree_description
                    scheme = None
                elif file_path.endswith('.workflow.yml'):
                    logger.debug("Loading workflow file: " + file_path)
                    loader = self.workflow_manager.load_workflow
                    scheme = None
                else:
                    continue

                try:
                    checker = schema_checker.Validator(scheme)
                    data = cache.get_or_load(file_path)
                    passed = checker.run(data)
                    for msg in checker.messages:
                        logger.warning('{:<40s} {}'.format(
                            os.path.basename(file_path), msg))
                    if not passed:
                        logger.info(
                            'YAML schema check failed for: ' + file_path)

                    loader(data, file_path)
                except Exception as error:
                    logger.exception('Error while loading %s', file_path)
                    logger.exception(error)
                    Messages.flowgraph_error = error
                    Messages.flowgraph_error_file = file_path
                    continue

        for key, block in self.blocks.items():
            category = self._block_categories.get(key, block.category)
            if not category:
                continue
            root = category[0]
            if root.startswith('[') and root.endswith(']'):
                category[0] = root[1:-1]
            else:
                category.insert(0, Constants.DEFAULT_BLOCK_MODULE_NAME)
            block.category = category

        self._docstring_extractor.finish()
        # self._docstring_extractor.wait()
        if 'options' not in self.blocks:
            # we didn't find one of the built-in blocks ("options")
            # which probably means the GRC blocks path is bad
            errstr = (
                "Failed to find built-in GRC blocks (specifically, the "
                "'options' block). Ensure your GRC block paths are correct "
                "and at least one points to your prefix installation:"
            )
            errstr = "\n".join([errstr] + (path or self.config.block_paths))
            raise RuntimeError(errstr)
        else:
            # might have some cleanup to do on the options block in particular
            utils.hide_bokeh_gui_options_if_not_installed(
                self.blocks['options'])

    def _iter_files_in_block_path(self, path=None, ext='yml'):
        """Iterator for block descriptions and category trees"""
        for entry in (path or self.config.block_paths):
            if os.path.isfile(entry):
                yield entry
            elif os.path.isdir(entry):
                for dirpath, dirnames, filenames in os.walk(entry):
                    for filename in sorted(filter(lambda f: f.endswith('.' + ext), filenames)):
                        yield os.path.join(dirpath, filename)
            else:
                logger.debug('Ignoring invalid path entry %r', entry)

    def _save_docstring_extraction_result(self, block_id, docstrings):
        docs = {}
        for match, docstring in docstrings.items():
            if not docstring or match.endswith('_sptr'):
                continue
            docs[match] = docstring.replace('\n\n', '\n').strip()
        try:
            self.blocks[block_id].documentation.update(docs)
        except KeyError:
            pass  # in tests platform might be gone...

    ##############################################
    # Description File Loaders
    ##############################################
    # region loaders
    def load_block_description(self, data, file_path):
        log = logger.getChild('block_loader')

        # don't load future block format versions
        file_format = data['file_format']
        if file_format < 1 or file_format > Constants.BLOCK_DESCRIPTION_FILE_FORMAT_VERSION:
            log.error('Unknown format version %d in %s',
                      file_format, file_path)
            return

        block_id = data['id'] = data['id'].rstrip('_')

        if block_id in self.block_classes_build_in:
            if block_id != 'options':
                # option block will not be overwritten because it already implemented in blocks/options.py
                log.warning('Not overwriting build-in block %s with %s',
                            block_id, file_path)
            return
        if block_id in self.blocks:
            log.warning('Block with id "%s" loaded from\n  %s\noverwritten by\n  %s',
                        block_id, self.blocks[block_id].loaded_from, file_path)

        try:
            block_cls = self.blocks[block_id] = self.new_block_class(**data)
            block_cls.loaded_from = file_path
        except errors.BlockLoadError as error:
            log.error('Unable to load block %s', block_id)
            log.exception(error)
            return

        self._docstring_extractor.query(
            block_id, block_cls.templates['imports'], block_cls.templates['make'],
        )

    def load_domain_description(self, data, file_path):
        log = logger.getChild('domain_loader')
        domain_id = data['id']
        if domain_id in self.domains:  # test against repeated keys
            log.debug('Domain "{}" already exists. Ignoring: %s', file_path)
            return

        color = data.get('color', '')
        if color.startswith('#'):
            try:
                tuple(int(color[o:o + 2], 16) / 255.0 for o in range(1, 6, 2))
            except ValueError:
                log.warning('Cannot parse color code "%s" in %s',
                            color, file_path)
                return

        self.domains[domain_id] = self.Domain(
            name=data.get('label', domain_id),
            multi_in=data.get('multiple_connections_per_input', True),
            multi_out=data.get('multiple_connections_per_output', False),
            color=color
        )
        for connection in data.get('templates', []):
            try:
                source_id, sink_id = connection.get('type', [])
            except ValueError:
                log.warn('Invalid connection template.')
                continue
            connection_id = str(source_id), str(sink_id)
            self.connection_templates[connection_id] = connection.get(
                'connect', '')
            self.cpp_connection_templates[connection_id] = connection.get(
                'cpp_connect', '')
            self.connection_params[connection_id] = connection.get('parameters', {})

    def load_category_tree_description(self, data, file_path):
        """Parse category tree file and add it to list"""
        log = logger.getChild('tree_loader')
        log.debug('Loading %s', file_path)
        path = []

        def load_category(name, elements):
            if not isinstance(name, str):
                log.debug('Invalid name %r', name)
                return
            path.append(name)
            for element in utils.to_list(elements):
                if isinstance(element, str):
                    block_id = element
                    self._block_categories[block_id] = list(path)
                elif isinstance(element, dict):
                    load_category(*next(iter(element.items())))
                else:
                    log.debug('Ignoring some elements of %s', name)
            path.pop()

        try:
            module_name, categories = next(iter(data.items()))
        except (AttributeError, StopIteration):
            log.warning('no valid data found')
        else:
            load_category(module_name, categories)

    ##############################################
    # Access
    ##############################################
    def parse_flow_graph(self, filename):
        """
        Parse a saved flow graph file.
        Ensure that the file exists, and passes the dtd check.

        Args:
            filename: the flow graph file

        Returns:
            nested data
        @throws exception if the validation fails
        """
        filename = filename or self.config.default_flow_graph
        is_xml = False
        with open(filename, encoding='utf-8') as fp:
            is_xml = '<flow_graph>' in fp.read(100)
            fp.seek(0)
            # todo: try
            if not is_xml:
                data = yaml.safe_load(fp)
                validator = schema_checker.Validator(
                    schema_checker.FLOW_GRAPH_SCHEME)
                validator.run(data)

        if is_xml:
            Messages.send('>>> Converting from XML\n')
            from ..converter.flow_graph import from_xml
            data = from_xml(filename)

        file_format = data.get('metadata', {}).get('file_format')
        if file_format is None:
            Messages.send(
                '>>> WARNING: Flow graph does not contain a file format version!\n')
        elif file_format == 0:
            Messages.send(
                '>>> WARNING: Flow graph format is version 0 (legacy) and will'
                ' be converted to version 1 or higher upon saving!\n')
        elif file_format > Constants.FLOW_GRAPH_FILE_FORMAT_VERSION:
            raise RuntimeError(
                f"Flow graph {filename} has unknown flow graph version!")

        return data

    def save_flow_graph(self, filename, flow_graph):
        data = flow_graph.export_data()

        try:
            data['connections'] = [
                yaml.ListFlowing(conn) if isinstance(conn, (list, tuple)) else conn
                for conn in data['connections']
            ]
        except KeyError:
            pass

        try:
            for d in chain([data['options']], data['blocks']):
                d['states']['coordinate'] = yaml.ListFlowing(
                    d['states']['coordinate'])
        except KeyError:
            pass

        out = yaml.dump(data, indent=2)

        replace = [
            ('blocks:\n', '\nblocks:\n'),
            ('connections:\n', '\nconnections:\n'),
            ('metadata:\n', '\nmetadata:\n'),
        ]
        for r in replace:
            out = out.replace(*r)

        with open(filename, 'w', encoding='utf-8') as fp:
            fp.write(out)

    def get_generate_options(self):
        for param in self.block_classes['options'].parameters_data:
            if param.get('id') == 'generate_options':
                break
        else:
            return []
        generate_mode_default = param.get('default')
        return [(value, name, value == generate_mode_default)
                for value, name in zip(param['options'], param['option_labels'])]

    def get_output_language(self):
        for param in self.block_classes['options'].parameters_data:
            if param.get('id') == 'output_language':
                break
        else:
            return []
        output_language_default = param.get('default')
        return [(value, name, value == output_language_default)
                for value, name in zip(param['options'], param['option_labels'])]

    ##############################################
    # Factories
    ##############################################
    Config = Config
    Domain = namedtuple('Domain', 'name multi_in multi_out color')
    Generator = Generator
    FlowGraph = FlowGraph
    Connection = Connection

    block_classes_build_in = blocks.build_ins
    # separates build-in from loaded blocks)
    block_classes = ChainMap({}, block_classes_build_in)

    port_classes = {
        None: ports.Port,  # default
        'clone': ports.PortClone,  # clone of ports with multiplicity > 1
    }
    param_classes = {
        None: params.Param,  # default
    }

    def make_flow_graph(self, from_filename=None):
        fg = self.FlowGraph(parent=self)
        if from_filename:
            data = self.parse_flow_graph(from_filename)
            fg.grc_file_path = from_filename
            fg.import_data(data)
        return fg

    def new_block_class(self, **data) -> Type[Block]:
        return blocks.build(**data)

    def make_block(self, parent, block_id, **kwargs) -> Block:
        cls = self.block_classes[block_id]
        return cls(parent, **kwargs)

    def make_param(self, parent, **kwargs):
        cls = self.param_classes[kwargs.pop('cls_key', None)]
        return cls(parent, **kwargs)

    def make_port(self, parent, **kwargs):
        cls = self.port_classes[kwargs.pop('cls_key', None)]
        return cls(parent, **kwargs)
